Inkjet recording apparatus

Abstract

An inkjet recording apparatus may include a corrugate mechanism configured to form a sheet into a corrugated shape. The inkjet recording apparatus may be configured to receive sheets of various sizes and shapes. Accordingly, in some examples, the inkjet recording apparatus may include differently configured portions to handle sheets of different sizes or shapes. According to one arrangement, the inkjet recording apparatus may be configured to receive passage of sheets of a first size through multiple ones of the differently configured portions while receiving passage of sheets of a second size though limited ones of the differently configured portions.

What is claimed is: 
     
       1. An inkjet recording apparatus, comprising:
 a first conveyor configured to selectively nip and convey a first sheet and a second sheet in a conveying direction, the second sheet having a shorter length in a first direction than the first sheet, the first direction being perpendicular to the conveying direction and a vertical direction; 
 a recording head comprising nozzles configured to eject ink droplets onto a sheet conveyed by the first conveyor; 
 a corrugate mechanism disposed upstream of the nozzles in the conveying direction and configured to form the sheet into a corrugated shape having alternating ridge portions and groove portions arranged in the first direction; 
 a plurality of second conveyors disposed downstream of the nozzles in the conveying direction and spaced from each other in the first direction, each of the plurality of second conveyors being spaced, in the conveying direction, from a corresponding first portion of the corrugate mechanism, the corresponding first portion configured to form one of the ridge portions in the sheet, the plurality of second conveyors being configured to nip the sheet at nip points and convey the sheet; and 
 a plurality of first pressing portions disposed downstream of the nozzles in the conveying direction and spaced from each other in the first direction, each of the plurality of first pressing portions being spaced, in the conveying direction, from a corresponding second portion of the corrugate mechanism, the corresponding second portion configured to form one of the groove portions in the sheet, the plurality of first pressing portions being configured to contact, at lower ends thererof, an upper surface of the sheet, and the lower ends being positioned lower than the nip points of the plurality of second conveyors, 
 wherein the inkjet recording apparatus defines a first zone configured to receive passage of the first sheet but not passage of the second sheet, and a second zone configured to receive passage of the first sheet and the second sheet, and 
 wherein the plurality of first pressing portions comprise first pressing portions positioned in the first zone and first pressing portions positioned in the second zone, and a pressing force per unit area configured to be applied to the sheet by the first pressing portions positioned in the second zone is less than a pressing force per unit area configured to be applied to the sheet by the first pressing portions positioned in the first zone. 
 
     
     
       2. The inkjet recording apparatus according to  claim 1 ,
 wherein the first pressing portions positioned in the first zone comprise:
 upstream pressing portions arranged in the first direction; and 
 downstream pressing portions disposed downstream of the upstream pressing portions in the conveying direction and arranged in the first direction, and 
 
 wherein each of the first pressing portions positioned in the second zone are arranged in a row with the upstream pressing portions positioned in the first zone. 
 
     
     
       3. The inkjet recording apparatus according to  claim 1 , wherein the first pressing portions positioned in the first zone and the first pressing portions positioned in the second zone are arranged in a single row. 
     
     
       4. The inkjet recording apparatus according to  claim 1 , wherein the plurality of first pressing portions are disposed downstream of the nip points of the plurality of second conveyors in the conveying direction. 
     
     
       5. The inkjet recording apparatus according to  claim 1 , further comprising:
 a discharge port through which the inkjet recording apparatus is configured to discharge the sheet; 
 a plurality of third conveyors disposed between the plurality of first pressing portions and the discharge port in the conveying direction, and spaced from each other in the first direction, each of the plurality of third conveyors being spaced from a corresponding second conveyor in the conveying direction, the plurality of third conveyors being configured to nip the sheet at nip points and convey the sheet; and 
 a plurality of second pressing portions arranged in a row with the plurality of third conveyors in the first direction and each spaced from a corresponding first pressing portion in the conveying direction, the plurality of second pressing portions being configured to contact, at lower ends thereof, the upper surface of the sheet, and the lower ends being positioned lower than the nip points of the plurality of third conveyors. 
 
     
     
       6. The inkjet recording apparatus according to  claim 5 , wherein the plurality of third conveyors are positioned in the first zone and the second zone, and the plurality of second pressing portions are positioned in the first zone but not positioned in the second zone. 
     
     
       7. The inkjet recording apparatus according to  claim 1 , further comprising a platen which includes a plurality of ribs disposed downstream of the first conveyor in the conveying direction and extending in the conveying direction, the plurality of ribs being spaced from each other in the first direction and configured to support, at upper edges thereof, the sheet, wherein the corrugate mechanism comprises:
 the plurality of ribs of the platen; and 
 a plurality of third pressing portions spaced from each other in the first direction and each interposed between a corresponding pair of the plurality of ribs, the plurality of third pressing portions being configured to contact, at lower ends thereof, the upper surface of the sheet held by the plurality of ribs, and the lower ends being lower than upper edges of the plurality of ribs. 
 
     
     
       8. The inkjet recording apparatus according to  claim 7 ,
 wherein the platen is configured to move up and down relative to the plurality of third pressing portions between a first position and a second position, 
 wherein the inkjet recording apparatus further comprises a plurality of urging members configured to urge the platen upward toward the first position, and 
 wherein the second zone is defined between a first part and a second part of the first zone in the first direction, and the plurality of urging members comprise an urging member positioned at a center of the second zone in the first direction, an urging member positioned in the first part, and an urging member positioned in the second part symmetrically to the urging member positioned in the first part relative to the urging member positioned at the center. 
 
     
     
       9. The inkjet recording apparatus according to  claim 8 , further comprising a support member configured to support the platen when the platen moves down into the second position,
 wherein each of the urging members is sandwiched between the platen and the support member, and 
 wherein the platen comprises a first protrusion and a second protrusion which protrude toward the support member and are positioned in the first part and the second part of the first zone respectively, and a portion of the platen between the first protrusion and the second protrusion is deformable toward the support member when the support member receives the first protrusion and the second protrusion of the platen in the second position. 
 
     
     
       10. The inkjet recording apparatus according to  claim 1 , wherein the plurality of first pressing portions comprise a plurality of spurs rotatably supported about an axis extending in the first direction. 
     
     
       11. The inkjet recording apparatus according to  claim 1 , wherein each of the plurality of first pressing portions comprises a pair of spurs spaced from each other in the first direction, and a spacer disposed between the pair of spurs. 
     
     
       12. The inkjet recording apparatus according to  claim 10 , wherein each of the plurality of first pressing portions comprises a resilient shaft for rotatably supporting a corresponding one of the plurality of spurs. 
     
     
       13. An inkjet recording apparatus, comprising:
 a first conveyor configured to selectively nip and convey a first sheet and a second sheet in a conveying direction, the second sheet having a shorter length in a first direction than the first sheet, the first direction being perpendicular to the conveying direction and a vertical direction; 
 a recording head comprising nozzles configured to eject ink droplets onto a sheet conveyed by the first conveyor; 
 a corrugate mechanism disposed upstream of the nozzles in the conveying direction and configured to form the sheet into a corrugated shape having alternating ridge portions and groove portions arranged in the first direction; 
 a plurality of second conveyors disposed downstream of the nozzles in the conveying direction and spaced from each other in the first direction, each of the plurality of second conveyors being spaced, in the conveying direction, from a corresponding first portion of the corrugate mechanism, the corresponding first portion configured to form one of the ridge portions in the sheet, the plurality of second conveyors being configured to nip the sheet at nip points and convey the sheet; and 
 a plurality of first pressing portions disposed downstream of the nozzles in the conveying direction and spaced from each other in the first direction, each of the plurality of first pressing portions being spaced, in the conveying direction, from a corresponding second portion of the corrugate mechanism, the corresponding second portion configured to form one of the groove portions in the sheet respectively, the plurality of first pressing portions being configured to contact, at lower ends thererof, an upper surface of the sheet, and the lower ends being positioned lower than the nip points of the plurality of second conveyors, 
 wherein the inkjet recording apparatus defines, in the first direction, a first zone configured to receive passage of the first sheet but not passage of the second sheet, and a second zone configured to receive passage of the first sheet and the second sheet, and 
 wherein the first pressing portions comprise upstream pressing portions positioned in the first zone and the second zone and arranged in the first direction, and downstream pressing portions positioned in the first zone but not in the second zone and arranged in the first direction at positions downstream of the upstream pressing portions in the conveying direction. 
 
     
     
       14. An inkjet recording apparatus, comprising:
 a first conveyor configured to selectively nip and convey a first sheet and a second sheet in a conveying direction, the second sheet having a shorter length in a first direction than the first sheet, the first direction being perpendicular to the conveying direction and a vertical direction; 
 a recording head comprising nozzles configured to eject ink droplets onto a sheet conveyed by the first conveyor; 
 a platen configured to move up and down between a first position and a second position and comprising a plurality of ribs disposed downstream of the first conveyor in the conveying direction and extending in the conveying direction, the plurality of ribs being spaced from each other in the first direction and configured to support, at upper edges thereof, the sheet conveyed by the first conveyor; 
 a plurality of pressing portions spaced from each other in the first direction and each interposed between a corresponding pair of the plurality of ribs, the plurality of pressing portions being configured to contact, at lower ends thereof, the upper surface of the sheet held by the plurality of ribs; 
 a support member configured to support the platen when the platen moves down into the second position; and 
 a plurality of urging members, each of the urging members being sandwiched between the platen and the support member and configured to urge the platen upward toward the first position, 
 wherein the inkjet recording apparatus define a first zone configured to receive passage of the first sheet but not passage of the second sheet, and a second zone configured to receive passage of the first sheet and the second sheet, and 
 wherein the platen further comprises a plurality of protrusions protruding toward the support member, and a portion of the platen positioned in the second zone is deformable toward the support member when the support member receives the plurality of protrusions of the platen in the second position. 
 
     
     
       15. The inkjet recording apparatus according to  claim 14 , wherein the second zone is defined between a first part and a second part of the first zone in the first direction, and the plurality of protrusions are positioned in the first part and the second part of the first zone but not positioned in the second zone.